The generation of diesel exhaust particle aerosols from a bulk source in an aerodynamic size range similar to atmospheric particles.

Cooney DJ, Hickey AJ - Int J Nanomedicine (2008)

Bottom Line:
Inertial impaction data indicated that the particle size distributions of the generated aerosols were trimodal, with count median aerodynamic diameters less than 100 nm.Scanning electron microscopy of deposited particles showed tightly aggregated particles, as would be expected from an evaporative process.Chemical analysis indicated that there were no major changes in the mass proportion of 2 specific aromatic hydrocarbons (benzo[a]pyrene and benzo[k]fluoranthene) in the particles resulting from the aerosolization process.

ABSTRACTThe influence of diesel exhaust particles (DEP) on the lungs and heart is currently a topic of great interest in inhalation toxicology. Epidemiological data and animal studies have implicated airborne particulate matter and DEP in increased morbidity and mortality due to a number of cardiopulmonary diseases including asthma, chronic obstructive pulmonary disorder, and lung cancer. The pathogeneses of these diseases are being studied using animal models and cell culture techniques. Real-time exposures to freshly combusted diesel fuel are complex and require significant infrastructure including engine operations, dilution air, and monitoring and control of gases. A method of generating DEP aerosols from a bulk source in an aerodynamic size range similar to atmospheric DEP would be a desirable and useful alternative. Metered dose inhaler technology was adopted to generate aerosols from suspensions of DEP in the propellant hydrofluoroalkane 134a. Inertial impaction data indicated that the particle size distributions of the generated aerosols were trimodal, with count median aerodynamic diameters less than 100 nm. Scanning electron microscopy of deposited particles showed tightly aggregated particles, as would be expected from an evaporative process. Chemical analysis indicated that there were no major changes in the mass proportion of 2 specific aromatic hydrocarbons (benzo[a]pyrene and benzo[k]fluoranthene) in the particles resulting from the aerosolization process.

f9-ijn-3-435: Concentrations of (a) benzo[a]pyrene (B[a]P) and (b) benzo[k]fluoranthene (B[k]F) as functions of the log of diesel exhaust particles (DEP) concentration calculated for bulk DEP and aerosols from 1.0 mg/g DEP suspensions that were freshly made or aged 6 months.

Mentions:
The recovery for the known PAH concentrations from the solid phase extraction columns was 92%–98% for B[a]P and 84%–92% for B[k]F over the range of concentrations and was not dependant on concentration. The calculated PAH concentrations as functions of the DEP concentration are shown in Figure 9. This figure also shows there were no obvious differences in the amount of PAH dissolved from bulk DEP or aged or fresh DEP aerosol. The relationship appears to be linear at low concentration, as expected, but not at the highest (~1.2 mg/mL) DEP concentration. This nonlinearity was likely due to a saturation of organic compounds in the DCM at high DEP concentrations.

f9-ijn-3-435: Concentrations of (a) benzo[a]pyrene (B[a]P) and (b) benzo[k]fluoranthene (B[k]F) as functions of the log of diesel exhaust particles (DEP) concentration calculated for bulk DEP and aerosols from 1.0 mg/g DEP suspensions that were freshly made or aged 6 months.

Mentions:
The recovery for the known PAH concentrations from the solid phase extraction columns was 92%–98% for B[a]P and 84%–92% for B[k]F over the range of concentrations and was not dependant on concentration. The calculated PAH concentrations as functions of the DEP concentration are shown in Figure 9. This figure also shows there were no obvious differences in the amount of PAH dissolved from bulk DEP or aged or fresh DEP aerosol. The relationship appears to be linear at low concentration, as expected, but not at the highest (~1.2 mg/mL) DEP concentration. This nonlinearity was likely due to a saturation of organic compounds in the DCM at high DEP concentrations.

Bottom Line:
Inertial impaction data indicated that the particle size distributions of the generated aerosols were trimodal, with count median aerodynamic diameters less than 100 nm.Scanning electron microscopy of deposited particles showed tightly aggregated particles, as would be expected from an evaporative process.Chemical analysis indicated that there were no major changes in the mass proportion of 2 specific aromatic hydrocarbons (benzo[a]pyrene and benzo[k]fluoranthene) in the particles resulting from the aerosolization process.

ABSTRACTThe influence of diesel exhaust particles (DEP) on the lungs and heart is currently a topic of great interest in inhalation toxicology. Epidemiological data and animal studies have implicated airborne particulate matter and DEP in increased morbidity and mortality due to a number of cardiopulmonary diseases including asthma, chronic obstructive pulmonary disorder, and lung cancer. The pathogeneses of these diseases are being studied using animal models and cell culture techniques. Real-time exposures to freshly combusted diesel fuel are complex and require significant infrastructure including engine operations, dilution air, and monitoring and control of gases. A method of generating DEP aerosols from a bulk source in an aerodynamic size range similar to atmospheric DEP would be a desirable and useful alternative. Metered dose inhaler technology was adopted to generate aerosols from suspensions of DEP in the propellant hydrofluoroalkane 134a. Inertial impaction data indicated that the particle size distributions of the generated aerosols were trimodal, with count median aerodynamic diameters less than 100 nm. Scanning electron microscopy of deposited particles showed tightly aggregated particles, as would be expected from an evaporative process. Chemical analysis indicated that there were no major changes in the mass proportion of 2 specific aromatic hydrocarbons (benzo[a]pyrene and benzo[k]fluoranthene) in the particles resulting from the aerosolization process.